MSW-820 Analogue Synthesizer

Roland DNA, rebuilt for 2026.

The MSW-820 is a compact, fader-heavy analog monosynth from Michigan Synth Works, and its roots run straight through the golden age of Roland mono synths. The oscillators are AS3340-based, the filter core is AS3109, the very same chip family that gave the SH-101, MC-202 and CMU-810 their unmistakable voice. This is that immediate, characterful Roland-style tone, rebuilt from the silicon up and handed a whole lot more to play with.

The headline is the filter. Sixteen modes, all analog, built around an AS3109 in a pole-mixing arrangement borrowed from the Caveman Totem module. Two banks of eight cover 24dB and 12dB lowpass, highpass, bandpass, notch, allpass and a generous run of hybrid responses that go well beyond the usual mono-synth menu. And hidden just above the cutoff sits a small attenuverter simply labelled THIS. Turn it up and VCO1's triangle routes straight into the filter at audio rate. Filter FM, right there on the panel, no patching required.

Two oscillators with saw, pulse and PWM, hard sync and glide. A second envelope, a digital noise source with eight flavors, and a syncable digital LFO with eight crossfadeable shapes. The whole thing runs from a single USB-C cable.

Small box. Deep synth.

Specifications

VCOs

• AS3340 Based, Pulse and Sawtooth Waveforms
• ENV Modulation (OSC1) and LFO Modulation (OSC2)
• Range: 16'/8'/4', 7 Octaves
• Pulse Width Modulation: 50% to Min
• PWM Mode: ENV/Manual/LFO Modulation
• Master and OSC2 (offset) Tune Control
• Pulse/Sawtooth Mixer control per Oscillator
• 2 Hard Sync Modes: O2 Track Pitch or O2 Do not track pitch
• 2 Reset Modes: Reset O1 on gate or Reset O1 and O2 on gate

Sound Mixer

• External Input (pre filter), OSC 1 Level
• OSC 2 Level
• Sub Osc Level tracking OSC1 with 1, 2, and 2 PWM Octave Settings
• Noise Level with 8 Noise Models: White, Pink, Hex Invert, Crackle, Orgone (pitched), Sonar (pitched)

VCF

• AS3109 based, 16 Modes. Low Pass, High Pass, Band Pass, Allpass (aka Phase)
• Cutoff Frequency: 10Hz to 20kHz
• Resonance: 0 to Self Oscillation
• CV Follow: 0-100%
• THIS knob (audio-rate filter modulation from OSC1's triangle output)
• Envelope Modulation via Attenuverter (-5 to 10)
• LFO Modulation via Attenuverter (-5 to 10)
• Pitch Modulation via Attenuverter (-5 to 10)
• External CV Modulation via Attenuverter (-5 to 10)

LFO

• Rate: 0.1 Hz to 22 Hz
• 8 Shapes with crossfade between shapes: Sine, Square, Ramp, Tri, Saw, Expo Decay, Random, Smoothed Random
• 2 Reset Modes: Reset on Gate, and Reset on Gate with Phase Control (via Fade knob)
• Fade Control (LFO Delay with Fade in)
• Bipolar Rate indicator

Envelopes

• Attack time: 1.5 ms to 2 s
• Decay time: 2 ms to 10 s
• Sustain Level: 0-100%
• Release Time: 2 ms to 10 s
• Modulation Envelope is hardwired to Modulation bus
• VCA Envelope is hardwired to VCA

VCA / Output Mixer

• VCA Control
• External Input (post filter/Env)

Inputs / Outputs

• MIDI IN, TRS 3.5mm PSIMIDI (either A or B)
• Clock IN to Control LFO Rate**
• Gate IN, 5-10V*
• V/Oct IN*
• Filter CV IN
• LFO Mod IN
• Audio IN
• Synth/Mix OUT
• USB-C IN/OUT, 5V Power 200 mA, DC Adapter included, also serves as USB MIDI

*Analog inputs override MIDI
**Overrides MIDI clock, switches LFO to clocked mode

MIDI Control

• LFO Shape: CC# 14
• LFO Rate (divisor when clocked): CC# 20
• LFO Reset to phase: CC# 22
• LFO sample and hold/release (switch @ 64): CC# 23
• Pitch bend up range*: CC# 3
• Pitch bend down range (use up range if zero)*: CC# 86
• Filter freq (via ExtCv slider): CC# 74
• Noise select*: CC# 30
• Noise click mode (switch @ 64): CC# 89
• Porta time*: CC# 5
• Porta on/off (switch @ 64)**: CC# 65
• Porta glide mode (switch @ 64): CC# 85
• Mod wheel: CC# 1
• Mod depth, LFO to Pitch amount in semitones*: CC# ??
• Velocity to filter mod amount*: CC# ??

*Setting is saved
**Saved, but only activated when MIDI is detected

Power

5V DC, 200 mA, USB-C (adapter included)

Dimensions

220 x 120 x 50 mm, 900 g